
<h1><span class="yiyi-st" id="yiyi-12">numpy.arcsin</span></h1>
        <blockquote>
        <p>原文：<a href="https://docs.scipy.org/doc/numpy/reference/generated/numpy.arcsin.html">https://docs.scipy.org/doc/numpy/reference/generated/numpy.arcsin.html</a></p>
        <p>译者：<a href="https://github.com/wizardforcel">飞龙</a> <a href="http://usyiyi.cn/">UsyiyiCN</a></p>
        <p>校对：（虚位以待）</p>
        </blockquote>
    
<dl class="data">
<dt id="numpy.arcsin"><span class="yiyi-st" id="yiyi-13"> <code class="descclassname">numpy.</code><code class="descname">arcsin</code><span class="sig-paren">(</span><em>x</em><span class="optional">[</span>, <em>out</em><span class="optional">]</span><span class="sig-paren">)</span><em class="property"> = &lt;ufunc &apos;arcsin&apos;&gt;</em></span></dt>
<dd><p><span class="yiyi-st" id="yiyi-14">反正弦，元素。</span></p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name">
<col class="field-body">
<tbody valign="top">
<tr class="field-odd field"><th class="field-name"><span class="yiyi-st" id="yiyi-15">参数：</span></th><td class="field-body"><p class="first"><span class="yiyi-st" id="yiyi-16"><strong>x</strong>：array_like</span></p>
<blockquote>
<div><p><span class="yiyi-st" id="yiyi-17"><em class="xref py py-obj">y</em>  - 坐标在单位圆上。</span></p>
</div></blockquote>
<p><span class="yiyi-st" id="yiyi-18"><strong>out</strong>：ndarray，可选</span></p>
<blockquote>
<div><p><span class="yiyi-st" id="yiyi-19">数组的形状与<em class="xref py py-obj">x</em>相同，其中用于存储结果。</span><span class="yiyi-st" id="yiyi-20">有关更多详细信息，请参阅<code class="xref py py-obj docutils literal"><span class="pre">doc.ufuncs</span></code>（“输出参数”部分）。</span></p>
</div></blockquote>
</td>
</tr>
<tr class="field-even field"><th class="field-name"><span class="yiyi-st" id="yiyi-21">返回：</span></th><td class="field-body"><p class="first"><span class="yiyi-st" id="yiyi-22"><strong>angle</strong>：ndarray</span></p>
<blockquote class="last">
<div><p><span class="yiyi-st" id="yiyi-23"><em class="xref py py-obj">x</em>中的每个元素的反正弦，以弧度和在闭合间隔<code class="docutils literal"><span class="pre">[-pi / 2，</span> <span class="pre">pi / 2]</span> </code>。</span><span class="yiyi-st" id="yiyi-24">如果<em class="xref py py-obj">x</em>是标量，则返回标量，否则返回一个数组。</span></p>
</div></blockquote>
</td>
</tr>
</tbody>
</table>
<div class="admonition seealso">
<p class="first admonition-title"><span class="yiyi-st" id="yiyi-25">也可以看看</span></p>
<p class="last"><span class="yiyi-st" id="yiyi-26"><a class="reference internal" href="numpy.sin.html#numpy.sin" title="numpy.sin"><code class="xref py py-obj docutils literal"><span class="pre">sin</span></code></a>, <a class="reference internal" href="numpy.cos.html#numpy.cos" title="numpy.cos"><code class="xref py py-obj docutils literal"><span class="pre">cos</span></code></a>, <a class="reference internal" href="numpy.arccos.html#numpy.arccos" title="numpy.arccos"><code class="xref py py-obj docutils literal"><span class="pre">arccos</span></code></a>, <a class="reference internal" href="numpy.tan.html#numpy.tan" title="numpy.tan"><code class="xref py py-obj docutils literal"><span class="pre">tan</span></code></a>, <a class="reference internal" href="numpy.arctan.html#numpy.arctan" title="numpy.arctan"><code class="xref py py-obj docutils literal"><span class="pre">arctan</span></code></a>, <a class="reference internal" href="numpy.arctan2.html#numpy.arctan2" title="numpy.arctan2"><code class="xref py py-obj docutils literal"><span class="pre">arctan2</span></code></a>, <code class="xref py py-obj docutils literal"><span class="pre">emath.arcsin</span></code></span></p>
</div>
<p class="rubric"><span class="yiyi-st" id="yiyi-27">笔记</span></p>
<p><span class="yiyi-st" id="yiyi-28"><a class="reference internal" href="#numpy.arcsin" title="numpy.arcsin"><code class="xref py py-obj docutils literal"><span class="pre">arcsin</span></code></a>是多值函数：对于每个<em class="xref py py-obj">x</em>，存在无限多个数字<em class="xref py py-obj">z</em>，使得<img alt="sin(z) = x" class="math" src="../../_images/math/277b58121fe9a49b5047753eee6c2b98e67c1519.png" style="vertical-align: -4px">。</span><span class="yiyi-st" id="yiyi-29">惯例是返回其实部在[-pi / 2，pi / 2]中的角度<em class="xref py py-obj">z</em>。</span></p>
<p><span class="yiyi-st" id="yiyi-30">对于实值输入数据类型，<em>arcsin</em>始终返回实际输出。</span><span class="yiyi-st" id="yiyi-31">对于不能表示为实数或无穷大的每个值，它会产生<code class="docutils literal"><span class="pre">nan</span></code>并设置<em class="xref py py-obj">无效</em>浮点错误标志。</span></p>
<p><span class="yiyi-st" id="yiyi-32">对于复值输入，<a class="reference internal" href="#numpy.arcsin" title="numpy.arcsin"><code class="xref py py-obj docutils literal"><span class="pre">arcsin</span></code></a>是一个复杂的分析函数，按照惯例，它具有分支切割[-inf，-1]和[1，inf]，并且从上面连续，从后面的后面。</span></p>
<p><span class="yiyi-st" id="yiyi-33">反正弦也称为<em class="xref py py-obj">asin</em>或sin ^ { -  1}。</span></p>
<p class="rubric"><span class="yiyi-st" id="yiyi-34">参考文献</span></p>
<p><span class="yiyi-st" id="yiyi-35">Abramowitz，M。和Stegun，I。</span><span class="yiyi-st" id="yiyi-36">A.，<em>Handbook of Mathematical Functions</em>，第10次印刷，New York：Dover，1964，</span><span class="yiyi-st" id="yiyi-37">79ff。</span><span class="yiyi-st" id="yiyi-38"><a class="reference external" href="http://www.math.sfu.ca/~cbm/aands/">http://www.math.sfu.ca/~cbm/aands/</a></span></p>
<p class="rubric"><span class="yiyi-st" id="yiyi-39">例子</span></p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">np</span><span class="o">.</span><span class="n">arcsin</span><span class="p">(</span><span class="mi">1</span><span class="p">)</span>     <span class="c1"># pi/2</span>
<span class="go">1.5707963267948966</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">np</span><span class="o">.</span><span class="n">arcsin</span><span class="p">(</span><span class="o">-</span><span class="mi">1</span><span class="p">)</span>    <span class="c1"># -pi/2</span>
<span class="go">-1.5707963267948966</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">np</span><span class="o">.</span><span class="n">arcsin</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span>
<span class="go">0.0</span>
</pre></div>
</div>
</dd></dl>
